/*
 * Copyright (c) 2013. wyouflf (wyouflf@gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.dongfang.net.http.client.callback;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.http.HttpEntity;

import android.text.TextUtils;

import com.dongfang.utils.IOUtils;

public class FileDownloadHandler {

	public File handleEntity(HttpEntity entity, RequestCallBackHandler callBackHandler, String target,
			boolean isResume, String responseFileName) throws IOException {
		if (entity == null || TextUtils.isEmpty(target)) {
			return null;
		}

		File targetFile = new File(target);

		if (!targetFile.exists()) {
			targetFile.createNewFile();
		}

		long current = 0;
		InputStream inputStream = null;
		FileOutputStream fileOutputStream = null;

		try {

			if (isResume) {
				current = targetFile.length();
				fileOutputStream = new FileOutputStream(target, true);
			}
			else {
				fileOutputStream = new FileOutputStream(target);
			}

			long total = entity.getContentLength() + current;

			if (callBackHandler != null && !callBackHandler.updateProgress(total, current, true)) {
				return targetFile;
			}

			inputStream = entity.getContent();
			BufferedInputStream bis = new BufferedInputStream(inputStream);

			byte[] tmp = new byte[4096];
			int len;
			while ((len = bis.read(tmp)) != -1) {
				fileOutputStream.write(tmp, 0, len);
				current += len;
				if (callBackHandler != null) {
					if (!callBackHandler.updateProgress(total, current, false)) {
						return targetFile;
					}
				}
			}
			fileOutputStream.flush();
			if (callBackHandler != null) {
				callBackHandler.updateProgress(total, current, true);
			}
		} finally {
			IOUtils.closeQuietly(inputStream);
			IOUtils.closeQuietly(fileOutputStream);
		}

		if (targetFile.exists() && !TextUtils.isEmpty(responseFileName)) {
			File newFile = new File(targetFile.getParent(), responseFileName);
			while (newFile.exists()) {
				newFile = new File(targetFile.getParent(), System.currentTimeMillis() + responseFileName);
			}
			return targetFile.renameTo(newFile) ? newFile : targetFile;
		}
		else {
			return targetFile;
		}
	}

}
